230 research outputs found
Optimized Design of Survivable MPLS over Optical Transport Networks. Optical Switching and Networking
In this paper we study different options for the survivability implementation
in MPLS over Optical Transport Networks in terms of network resource usage and
configuration cost. We investigate two approaches to the survivability
deployment: single layer and multilayer survivability and present various
methods for spare capacity allocation (SCA) to reroute disrupted traffic. The
comparative analysis shows the influence of the traffic granularity on the
survivability cost: for high bandwidth LSPs, close to the optical channel
capacity, the multilayer survivability outperforms the single layer one,
whereas for low bandwidth LSPs the single layer survivability is more
cost-efficient. For the multilayer survivability we demonstrate that by mapping
efficiently the spare capacity of the MPLS layer onto the resources of the
optical layer one can achieve up to 22% savings in the total configuration cost
and up to 37% in the optical layer cost. Further savings (up to 9 %) in the
wavelength use can be obtained with the integrated approach to network
configuration over the sequential one, however, at the increase in the
optimization problem complexity. These results are based on a cost model with
actual technology pricing and were obtained for networks targeted to a
nationwide coverage
On QoS-assured degraded provisioning in service-differentiated multi-layer elastic optical networks
The emergence of new network applications is driving network operators to not
only fulfill dynamic bandwidth requirements, but offer various grades of
service. Degraded provisioning provides an effective solution to flexibly
allocate resources in various dimensions to reduce blocking for differentiated
demands when network congestion occurs. In this work, we investigate the novel
problem of online degraded provisioning in service-differentiated multi-layer
networks with optical elasticity. Quality of Service (QoS) is assured by
service-holding-time prolongation and immediate access as soon as the service
arrives without set-up delay. We decompose the problem into degraded routing
and degraded resource allocation stages, and design polynomial-time algorithms
with the enhanced multi-layer architecture to increase the network flexibility
in temporal and spectral dimensions. Illustrative results verify that we can
achieve significant reduction of network service failures, especially for
requests with higher priorities. The results also indicate that degradation in
optical layer can increase the network capacity, while the degradation in
electric layer provides flexible time-bandwidth exchange.Comment: accepted by IEEE GLOBECOM 201
Survivable MPLS Over Optical Transport Networks: Cost and Resource Usage Analysis
In this paper we study different options for the survivability implementation
in MPLS over Optical Transport Networks (OTN) in terms of network resource
usage and configuration cost. We investigate two approaches to the
survivability deployment: single layer and multilayer survivability and present
various methods for spare capacity allocation (SCA) to reroute disrupted
traffic. The comparative analysis shows the influence of the offered traffic
granularity and the physical network structure on the survivability cost: for
high bandwidth LSPs, close to the optical channel capacity, the multilayer
survivability outperforms the single layer one, whereas for low bandwidth LSPs
the single layer survivability is more cost-efficient. On the other hand,
sparse networks of low connectivity parameter use more wavelengths for optical
path routing and increase the configuration cost, as compared with dense
networks. We demonstrate that by mapping efficiently the spare capacity of the
MPLS layer onto the resources of the optical layer one can achieve up to 22%
savings in the total configuration cost and up to 37% in the optical layer
cost. Further savings (up to 9 %) in the wavelength use can be obtained with
the integrated approach to network configuration over the sequential one,
however, at the increase in the optimization problem complexity. These results
are based on a cost model with different cost variations, and were obtained for
networks targeted to a nationwide coverage
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